Rep:Mod:DUT2015

NH₃ molecule

Project molecule

• Molecule Name: Ammonia
• Calculation method: RB3LYP
• Basis set: 6-31G(D,P)
• Final energy E(RB3LYP) in atomic units (au): -56.55776873 a.u.
• RMS gradient: 0.00000485 a.u.
• Point group: C3v
• Optimized Bond Distance? 1.3 Å
• Optimised H-N-H bond angle: 109.471

Item                       Value     Threshold  Converged?

 Maximum Force            0.000004     0.000450     YES

 RMS     Force            0.000004     0.000300     YES

 Maximum Displacement     0.000072     0.001800     YES

 RMS     Displacement     0.000035     0.001200     YES

Predicted change in Energy=-5.986329D-10

 Optimization completed.

    -- Stationary point found.

NH₃ Log File File:DavidTyoember NH3.LOG

Optimized Ammonia Molecule

I would expect 6 (3x4 - 6) modes from the 3N-6 rule.

• From the vibrations window included you can see that 2 pairs of asymmetric bending modes are degenerate.
• The first 3 in the table are Bending mode vibrations and the last 3 are stretching vibrations
• Bending modes 1 and 4 in the table are highly symmetric.
• Mode 1 in the table is known as the umbrella mode.

Below is an image showing the charges present on the NH₃ Molecule.